<?php
/**
 * Try to automatically generate the script necessary for postMessage to work.
 * for documentation see https://github.com/aristath/kirki/wiki/required
 *
 * @package     Kirki
 * @category    Core
 * @author      Aristeides Stathopoulos
 * @copyright   Copyright (c) 2016, Aristeides Stathopoulos
 * @license     http://opensource.org/licenses/gpl-2.0.php GNU Public License
 * @since       1.0
 */

// Exit if accessed directly
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

if ( ! class_exists( 'Kirki_Customizer_Scripts_PostMessage' ) ) {
	class Kirki_Customizer_Scripts_PostMessage extends Kirki_Customizer_Scripts {

		/**
		 * string.
		 * The script generated for ALL fields
		 */
		public static $postmessage_script = '';
		/**
		 * boolean.
		 * Whether the script has already been added to the customizer or not.
		 */
		public static $script_added = false;

		/**
		 * The class constructor
		 */
		public function __construct() {
			add_action( 'wp_footer', array( $this, 'enqueue_script' ), 21 );
		}

		/**
		 * Generates the scripts needed for postMessage.
		 * This works on a per-field basis.
		 * Once created, the script is added to the $postmessage_script property.
		 *
		 * @param array the field definition
		 * @return void
		 */
		public static function generate_script( $args = array() ) {

			$script = '';
			/**
			 * If in our config we've set 'postMessage' to 'auto',
			 * then use the 'output' argument to auto-generate the js_vars
			 */
			$config_id = ( isset( $args['kirki_config'] ) ) ? $args['kirki_config'] : 'global';
			if ( isset( Kirki::$config[ $config_id ]['postMessage'] ) && 'auto' == Kirki::$config[ $config_id ]['postMessage'] ) {
				if ( ! isset( $args['js_vars'] ) || empty( $args['js_vars'] ) ) {
					if ( isset( $args['output'] ) ) {
						$args['js_vars']   = $args['output'];
						$args['transport'] = 'postMessage';
					}
				}
			}

			/**
			 * Make sure "transport" is defined
			 */
			$args['transport'] = ( isset( $args['transport'] ) ) ? $args['transport'] : 'refresh';
			/**
			 * Make sure that we need to proceed
			 */
			if ( isset( $args['js_vars'] ) && 'postMessage' == $args['transport'] ) {
				/**
				 * Make sure that "js_vars" is an array.
				 * If not, then early exit with return.
				 */
				if ( ! is_array( $args['js_vars'] ) || empty( $args['js_vars'] ) ) {
					return;
				}
				/**
				 * Start looping through all the "js_vars" items in the array.
				 * Documentation on how to use the "js_vars" argument and its syntax
				 * can be found on https://github.com/aristath/kirki/wiki/js_vars
				 */
				foreach ( $args['js_vars'] as $js_vars ) {
					/**
					 * Sanitize the arguments
					 */
					$js_vars = array(
						'element'     => ( isset( $js_vars['element'] ) ) ? sanitize_text_field( $js_vars['element'] ) : '',
						'function'    => ( isset( $js_vars['function'] ) ) ? esc_js( $js_vars['function'] ) : 'css',
						'property'    => ( isset( $js_vars['property'] ) ) ? esc_js( $js_vars['property'] ) : '',
						'units'       => ( isset( $js_vars['units'] ) ) ? esc_js( $js_vars['units'] ) : '',
						'prefix'      => ( isset( $js_vars['prefix'] ) ) ? esc_js( $js_vars['prefix'] ) : '',
						'suffix'      => ( isset( $js_vars['suffix'] ) ) ? esc_js( $js_vars['suffix'] ) : '',
						'js_callback' => ( isset( $js_vars['js_callback'] ) ) ? esc_js( $js_vars['js_callback'] ) : '',
					);

					$settings    = $args['settings'];
					$prefix      = ( ! empty( $js_vars['prefix'] ) ) ? $js_vars['prefix'] . ' + ' : '';
					$units       = ( ! empty( $js_vars['units'] ) ) ? ' + ' . $js_vars['units'] : '';
					$suffix      = ( ! empty( $js_vars['suffix'] ) ) ? $js_vars['suffix'] : '';
					$js_callback = ( ! empty( $js_vars['js_callback'] ) ) ? $js_vars['js_callback'] : '';

					$script .= 'wp.customize( \'' . $settings . '\', function( value ) {';
					$script .= 'value.bind( function( newval ) {';

					if ( 'html' == $js_vars['function'] ) {

						$script .= '$(\'' . $js_vars['element'] . '\').html( newval );';

						// execute js_callback (callback must exist in dom before this script - see priority on the action/
						if ( ! empty( $js_callback ) ) {
							$script .= $js_callback . '(\'' . $js_vars['element'] . '\', newval);'; // js_callback(element, newval);
						}

					} else if ( 'style' == $js_vars['function'] ) {

						$styleID = uniqid( 'kirki-style-' );

						// append unique style tag if not exist
						$script .= 'if( !$(\'#' . $styleID . '\').size() ) {';
						$script .= '$(\'head\').append(\'<style id="' . $styleID . '"></style>\');';
						$script .= '}';

						// if we have new value, replace style contents with custom css
						$script .= 'if( newval !== \'\') {';
						$script .= '$(\'#' . $styleID . '\').text(\'' . $js_vars['element'] . '{ ' . $js_vars['property'] . ':' . $prefix . '\' + newval + \'' . $units . $suffix . ';}\');';

						// else let's clear it out
						$script .= '}else{';
						$script .= '$(\'#' . $styleID . '\').text(\'\');';
						$script .= '}';

						// execute js_callback (callback must exist in dom before this script - see priority on line 41
						if ( ! empty( $js_callback ) ) {
							$script .= $js_callback . '(\'' . $js_vars['element'] . '\', newval);'; // js_callback(element, newval);
						}

					} else {
						$units  = ( ! empty( $js_vars['units'] ) ) ? " + '" . $js_vars['units'] . "'" : '';
						$prefix = ( ! empty( $js_vars['prefix'] ) ) ? "'" . $js_vars['prefix'] . "' + " : '';

						// append inline css - rules are very strict
						if ( ' !important' === $suffix || '!important' === $suffix ) {
							// this.style.setProperty( 'color', 'red', 'important' ); - jquery won't fix .css !important issue so we go oldschool
							$script .= '$(\'' . $js_vars['element'] . '\').each(function(){ this.style.setProperty(\'' . $js_vars['property'] . '\', ' . $prefix . 'newval' . $units . ', \'important\');});';
						} else {
							// $suffix = what other suffix exists inline?
							$script .= '$(\'' . $js_vars['element'] . '\').' . $js_vars['function'] . '(\'' . $js_vars['property'] . '\', ' . $prefix . 'newval' . $units . ' );';
						}

						// execute js_callback (callback must exist in dom before this script - see priority on action
						if ( ! empty( $js_callback ) ) {
							$script .= $js_callback . '(\'' . $js_vars['element'] . '\', newval);'; // js_callback(element, newval);
						}

					}

					$script .= '}); });';

				}

			}

			self::$postmessage_script .= $script;

		}

		/**
		 * Format the script in a way that will be compatible with WordPress.
		 *
		 * @return  void (echoes the script)
		 */
		public function enqueue_script() {
			if ( ! self::$script_added && '' != self::$postmessage_script ) {
				self::$script_added = true;
				echo '<script>jQuery(document).ready(function($) { "use strict"; ' . self::$postmessage_script . '});</script>';
			}
		}

	}
}